Yes, it's a bad idea. Small appliances all are built with that 18" in mind.

With ~7.5' ceilings, I wouldn't want 42" uppers for purely aesthetic reasons even if 15" clearance over the counter were functional. It's going to be a very heavy, overwhelming look.

You're probably not losing that much usable storage by going to 36", and you could likely make up for it elsewhere. I have ~8' ceilings and ~36" uppers and they are very functional.

That's what I needed to know! I was afraid it would be a "heavy, overwhelming look". We are raising a dropped ceiling to gain an extra 10". I currrently have 30" cabinets so even a 36" upper will be nice. Thanks a bunch!

“Is 15" enough space between upper cabinet and countertops?”

It is exactly enough space to fit a 15” Dancing Baby Groot figurine. I’m not sure anything else matters. 😂

15" between counter and upper cabinets is a bit tight and most will feel like your kitchen is "falling down" when they visit. You want at least 18".

Good decision keeping the 18”. Good luck with the reno!

That's great to know! I would love to see other photos if you're able. I'm still working on the layout. Thanks!

I typically put the cabinets at 16". None of the kitchens look like they are "falling down"! I've never had a problem with appliances fitting underneath, either. Even the KitchenAid mixer isn't a problem, as I always pull it forward to use anyway.

My 1960's kitchen has 15 inches. I hate it. The kitchen aid does NOT fit underneath, the microwave barely fits. I'm short and it is NOT helpful for "reaching things," it just is a pain in the rear end. I hope you didn't do it.

18" is the "standard" backsplash height. Small appliance manufacturers use that standard when designing their appliances. If you go with 15", you will likely not be able to fit a coffeemaker, mixer, or other small appliance under the cabinets - whether they're sitting on the counter or just there when in use.

When using small appliances on the counter, if you cannot fit them under the cabinets, you will need to use them close to the edge of your counters in the approximately 12" in front of the upper cabinets (that assumes 12"D uppers + 1" for door; if your uppers are deeper, then there will be even less counter frontage to work with).

I would stick with 18" -- and that's b/w whatever is the lowest part of the uppers - cabinets or light rail.

Realistically, would the top 6" of a 42" tall cabinet be usable? You also don't want to overwhelm a smaller-than-normal space (height-wise).

Well darn! I just realized this thread is over a year old - too late to be of any use to the orignal poster. I'm usually good at noticing if someone has resurrected an old thread, but I missed it this time!

It’s an odd question anyway. People should know what small appliances they have or want, and have a ruler to measure.